Cages used in holding small animals such as dogs, cats, rabbits, monkeys and the like used for laboratory research and as temporary holding structures for veterinary purposes often employ a shelf extending between the opposite side walls of the cage for animals, particularly cats, to perch on. In the case of felines, a litter box is emplaced on the bottom wall of the cage and a shelf for perching placed an upward distance from the cage bottom.
Heretofore, shelves used in cages were not universal in fit and merely existed of a tray cut to size with an end flange and fastened through existing or otherwise formed hole or bolt patterns in the cage walls. When the shelves and cages were produced by different manufacturers, particular cutting and shaping to size was required and drilling through the cage wall was needed. Thus, fitting shelves was often a difficult and time consuming job even though apparently quite simple at the outset.